Resistance unit for electrical apparatus.



A. 5. LoGmN. RESISTANCE UNTT FOR ELECTRTCAL APPARATUS. APPLICATION FILE APR. 3. T915.

l, "FLA 059. Patented Feb. 8,19%).

WITNEM' l INVENTOR ALEXANDER J. LOGUIN, OF PETROGRAD, RUSSIA.

RESISTANCE UNIT FOR ELECTRICAL APPARATUS.

Specification of LettersPatent.

ifatentea Feb. s, 1916.

Application filed April 1915. p Serial No. 18,937.

T0 all whom t may concern:

Be it known that I, ALEXANDER J. LOGUIN, residing at Petrograd, Russia, a subject of the Emperor of Russia, have invented or discovered certain new and useful Improvements in Resistance Units for'Electrical Apparatus,of which improvements the'following is a specification.

My invention relates to improvements in electrical apparatus and, generally stated, consists in a coil formed of an electrical conductor having by virtue of its shape peculiar advantages. This coil is applicable in electrical engineering generally, wherever its advantages are of importance; but, more specifically, it is applicable as a unit in the building of resistance boxes and like pieces of apparatus.

The invention is illustrated in the accompanying drawings, in which- Figure lshows in side elevation a resistance unit of my invention; Fig. 2 shows an end view of the same; Fig. 3 shows in side and end elevation the tools employed in forming and the manner of forming such a coil as is embodied in the resistance unit of Figs. l and 2; rig. i shows in longitudinal `section through the supporting plate of a resistance bor; a succession of resistance units such as that of Fig. l, arranged in operative relative positions; and Fig. 5 is a .view corresponding to Fig. 2, and showing in plan a resistance unit Whose coil einbodies my invention generically but is speciiically different from that of rigs. l and 2.

The coil which is the essential element' of the resistance unit shown in Figs. l and 2 is a helix whose convolutions are in plan,

not circular, as is usual, but are elongate, consisting of sharp bends l, 2, 3, 4, etc., alternating with straight or nearly straight portions l--2, 2-3, 3%, etc. The succeeding turns of this coil are not arranged in parallelism, as is usual, but are-stepped; the homologous parts of the vadjacent turnsare non-parallel. Compare the portions 1 2 and 3-4 of the coil shown in Fig. 2. Figs.

l and .2 show an orderly succession vof the v stepping or non-parallclisin of the turns. Fig. 2 shows the outermost portions of the coil lying in a cylindrical surface, and comparison of Figs. 2 and 1 will make plain the fact that in this particular coil these outermost portions (l, 2, 3, 1l, etc.) lie in and deiine two truly helical lines in that cylindrical surface.

A convenient and simple way of forming such a coil is indicated in Fig. 3. A mandrel is provided, consisting of the three parts IO, Il, and 12 which, when the parts are assembled (see the end view) has approximately the shape in cross section which it is desired to reproduce in the turns of the coil. Upo'n this mandrel the wire is wrapped to form the coil. The ,view in side elevation shows the wrapping in progress. lVhen the wrapping is completed the mandrel is removed; it will be observed that the' central member of the three-part mandrel is made of tapered form to facilitate the knocking down and removal of the mandrel. When the mandrel is removed the resilience of the metal will cause the coil to spring from the truly tubular form in which it was laid down to the expanded form shown in Figs. l and 2. It will be understood that elasticity of material and degree'aiid uniformity of tension in winding and the closeness with which the turns are laid upon the mandrel, and even the minute shape of the mandrel itself are variables which maybe suited to the end in view. l

The characteristics of such a coil as I have now particularly described are advantageous in that danger of short-circuits is greatly reduced, and this point becomes important when dealing with `great lengths of light wire, while access of air for ventilation is greatly facilitated. I mean here to indicate certain advantages, not to afford a complete catalogue of advantages under all possible conditions ofservice.

A unit for a resistance box embodying such a coil as I have described is particularly shown in the drawings. It includes a supporting rod 9, enveloped in insulation throughout its middle part, around which insulating envelop the coil extends. At one end the coil is electrically united with the supporting rod. The other en d of the rod may be screw threaded, as shown. to receive jam-nuts for making'electric connection.

The turns of the coils are shown to be tangent to the envelop of insulating ma- `terial which surrounds rod 9, and all or some of them may be secured, if desired, to the insulating envelop by asbestos adhesive tape, by fire-proof cement, or by any other preferred means. Or, as will generally be the case, the coil may rest on its core without special securing.` The springiness'of the structure as a whole may be made to -a suitable' binding-post l?.

aii'ord some security, it desired; Mani festly, the coil may be mounted on any proper cylindrical body, and suitably insulated, either by the character ot' the support or otherwise.

Fig. l shows the assembly of such units as l have described in a resistance box. rlhey are mountedpn a common slab or plate oi insulating material, as slate or marble, each rod 9 being providedL with a head 13 and with a nut la on its screwthreaded adjacent portion to effect. securel mounting. Between the jam-nuts lit and l5 of each unit is secured 4the tree end ot the coil ot' the adjacent unit. When a series of -units is so mounted and connected thel'supporting rod 9 ot the unit at one end of the series and the vit'reeend ot the coil offthe unit at the other end of the series are connected linI .the circuit 1n which the apparatus 1s to loe used. lig. l further shows a contactv 16, which may be adjustable and applicable to any loop of a coil, and a tap Wire leading to This detail renders the apparatus as a Whole still more flexible to meet service conditions.

l have illustrated the resistance unit apA nrt/near and radiating ability, and is furthermore more rigid and strong.

ln Fig. 5 l have shown that my invention is not limited in the matter ot the shape oit i helically wound conductor for electric current, each turn ot the helix being elongate in plan and the succeeding turns being non-parallel to one another. ,f

2. it helically wound conductor tor. electric current the successive turns of the helix being alike in plan, asymmetrical with respect to the airis ot the helix, and the homologous portions of the turns Yitollowing one another in helical succession. y

3. tn electric conductor termedl into a coil., each turn ot said coil .being elongate in plan, and the turns succeeding one another in stepped arrangement.

ln 'testimony "whereof have hereunto set my hand.

ALEXANDER d'. LGllllil.

"Witnesses 2 Pant ltl. Cnrrorrriow, Fri/incre J. Terrasson. 

